[Pulmonary fibro-xanthogranuloma associated with renal amyloidosis in a 5-year-old child].

Background: Pulmonary fibroxanthogranuloma is a benign tumor that is rarely seen in children. Its association with renal amyloidosis is not known.

Case report: A 5 year-old boy developed arthritis in his wrists and his hands became clubbed. X-rays showed a round mass in the left inferior pulmonary lobe. Sonography revealed that this mass contained fluid. Nephrotic syndrome appeared one month later. The pulmonary mass was then excised; histology indicated a fibroxanthogranuloma with no malignancy. Renal biopsy showed infiltration with amyloid substance. The nephrotic syndrome was improved one month after surgery, but contact with the child was then lost.

Conclusion: The association of this tumor with apparently secondary amyloidosis may indicate that fibroxanthogranuloma is a pseudotumor of inflammatory origin.